MI5 Fragmentation of pristine mires

>> Background information

Development

Almost the whole of Finland's total mire area remained in a relatively pristine state until the 1950s when the large-scale draining of mires for forestry was initiated.

In this natural state, the size distribution of mires resembled a bell-shaped curve in southern Finland where average sized mire pacthes (10-500 ha) contributed more than half of the area. In northern Finland there were relatively more large mires (over 2 000 ha).

At present, the distribution of pristine mires has shifted quite heavily towards the smaller size classes. Larger uniform mires have been been fragmented into several patches ofdrained and pristine mires. Some areas have even been so effectively tranformed that they may be now classified as some others habitat type (mainly as forest).

Impacts of fragmentation